Catalyst for preparing lactone and a method for preparing lactone

Abstract

The present invention relates to a catalyst for preparing a lactone, which is prepared by supporting a cupric compound, a zinc compound and at least one alkaline earth metal compound on the supporter. The present invention also relates to a method for preparing a lactone, which comprises a dehydrocyclization reaction of a diol under a gas phase in the presence of the aforementioned catalyst after activating said catalyst. The catalyst for preparing lactone of the present invention is quite economic because of its high activity, long lifetime and high selectivity of products.

What is claimed is:  
     
       1. A catalyst for preparing a lactone, which is prepared by supporting a cupric compound, a zinc compound and at least one alkaline earth metal compound on the supporter. 
     
     
       2. A catalyst according to claim  1 , wherein the material of said supporter is selected from a group consisting of silica, alumina, and their mixture. 
     
     
       3. A catalyst according to claim  1 , wherein said cupric compound is selected from a group consisting of copper (II) nitrate, copper (II) carbonate, copper (II) acetate, copper (II) chloride, copper (II) hydroxide, copper (II) phosphate and copper (II) sulfate. 
     
     
       4. A catalyst according to claim  1 , wherein said zinc compound is selected from a group consisting of zinc nitrate, zinc carbonate, zinc acetate, zinc chloride, zinc hydroxide and zinc sulfate. 
     
     
       5. A catalyst according to claim  1 , wherein said alkaline earth metal compound is selected from a group consisting of carbonate, hydroxide, silicate and phosphate of beryllium, magnesium, calcium, strontium or barium. 
     
     
       6. A catalyst according to claim  1 , wherein the ratio of cupric compound to zinc compound is 6:1 to 1:2 by weight in terms of copper (II) oxide and zinc oxide. 
     
     
       7. A catalyst according to claim  1 , wherein the amount of alkaline earth metal compound is 0.01 to 10 wt % based on the total weight of copper (II) oxide and zinc oxide in terms of oxides, when one of the alkaline earth metal compounds selected from a group consisting of magnesium, calcium and barium is used. 
     
     
       8. A catalyst according to claim  1 , wherein the amount of alkaline earth metal compound is 0.5 to 20 wt % based on the total weight of copper (II) oxide and zinc oxide in terms of oxides, when two of the alkaline earth metal compounds selected from a group consisting of magnesium, calcium and barium are used. 
     
     
       9. A method for preparing a lactone, which comprises a dehydrocyclization reaction of a diol under a gas phase in the presence of a catalyst according to any one of claim  1  to claim  8  after activating said catalyst. 
     
     
       10. A method according to claim  9 , wherein said lactone is selected from a group consisting of β-propiolactone, β-butyrolactone, γ-butyrolactone, γ-valerolactone, δ-butyrolactone, γ-caprolactone, ε-caprolactone, δ-hydroxyoctylic acid lactone, δ-hydroxynonylic acid lactone, γ-hydroxydecylic acid lactone and δ-hydroxydecylic acid lactone. 
     
     
       11. A method according to claim  9 , wherein said diol is selected from a group consisting of 1,3-propylene glycol, 2-methyl-1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,4-petanediol, 1,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol and 1,10-decanediol. 
     
     
       12. A method according to claim  9 , wherein said lactone is γ-butyrolactone and said diol is 1,4-butylene glycol. 
     
     
       13. A method according to claim  9 , wherein said catalyst is reduced to activate at a temperature ranging from 180 to 250° C. for 6 to 20 hours with hydrogen gas. 
     
     
       14. A method according to claim  9 , wherein said dehydrocyclization reaction is carried out at a temperature ranging from 160 to 280° C. 
     
     
       15. A method according to claim  12 , wherein said dehydrocyclization reaction is carried out in a molar ratio of hydrogen gas to 1,4-butylene glycol ranging from (12 to 1):1. 
     
     
       16. A method according to claim  12 , wherein said dehydrocyclization reaction is carried out with the gas hourly space velocity of 1,4-butylene glycol ranging from 10 to 20,000 hr −1 . 
     
     
       17. A method according to claim  9 , wherein the catalyst bed used for said dehydrocyclization reaction is a fixed bed. 
     
     
       18. A method according to claim  9 , wherein the catalyst bed used for said